A confidential government document containing evidence so critical it had the potential to change the course of an American tragedy was kept in the dark for more than a decade. In 2007, a team of federal prosecutors built a case that Purdue Pharma, the maker of the powerful opioid, OxyContin, knew early on that the drug was fueling a rise in addiction and abuse. They also gathered evidence that the company’s executives had misled Congress and the public. THE WEEKLY shines a light on a decade-old Justice Department investigation, that could have major consequences for today’s wave of lawsuits against opioid makers. (Episode 10 of 30)